The multifaceted link between inflammation and human diseases.

Increasing reports on epidemiological, diagnostic, and clinical studies suggest that dysfunction of the inflammatory reaction results in chronic illnesses such as cancer, arthritis, arteriosclerosis, neurological disorders, liver diseases, and renal disorders. Chronic inflammation might progress if injurious agent persists; however, more typically than not, the response is chronic from the start. Distinct to most changes in acute inflammation, chronic inflammation is characterized by the infiltration of damaged tissue by mononuclear cells like macrophages, lymphocytes, and plasma cells, in addition to tissue destruction and attempts to repair. Phagocytes are the key players in the chronic inflammatory response. However, the important drawback is the activation of pathological phagocytes, which might result from continued tissue damage and lead to harmful diseases. The longer the inflammation persists, the greater the chance for the establishment of human diseases. The aim of this review was to focus on advances in the understanding of chronic inflammation and to summarize the impact and involvement of inflammatory agents in certain human diseases.

Adipose-derived stem cells decrease cardiomyocyte damage induced by porphyromonas gingivalis endotoxin through suppressing hypertrophy, apoptosis, fibrosis, and MAPK markers.

Heart failure is one of the complications related to periodontal disease. In addition to drugs or herbal medicines, stem cell therapy shows potential in the treatment of cardiomyopathy. This study investigates if stem cells exhibit beneficial effects on cardiomyocyte damage induced by porphyromonas gingivalis endotoxin (Pg-LPS). From the experimental results we find that Pg-LPS reduce cardiomyocyte viability via the activation of apoptosis, hypertrophy, fibrosis and MAPK signaling. Pg-LPS damaged cardiomyocytes co-cultured with adipose-derived stem cells (ADSC) increases cardiomyocyte viability through suppressing the pathological markers described above. Further evidence implies that survival marker, IGF1, secreted from ADSC, may play an important role in the Pg-LPS induced protective effect on cardiomyocyte damage.

Tanshinone-induced ERs suppresses IGFII activation to alleviate Ang II-mediated cardiac hypertrophy.

Cardiomyopathy involves changes in myocardial ultrastructure and cardiac hypertrophy. Angiotensin II (AngII) has previously been shown to stimulate the expression of IGF-2 and IGF-2R in H9c2 cardiomyoblasts and increase of blood pressure, and cardiac hypertrophy. Estrogen receptors (ERs) exert protective effects, such as anti-hypertrophy in cadiomyocytes. Tanshinone IIA (TSN), a main active ingredient from a Chinese medical herb, Salvia miltiorrhiza Bunge (Danshen), was shown to protect cardiomyocytes hypertrophy by different stress signals. We aimed to investigate whether TSN protected H9c2 cardiomyocytes from AngII-induced activation of IGF-2R pathway and hypertrophy by mediating through ERs. AngII resulted in H9c2 cardiomyoblast hypertrophy and increased inflammatory molecular markers. These were down-regulated by TSN via estrogen receptors. AngII resulted in elevation in MAPKs, IGF-2R and hypertrophic protein markers. These, again, were reduced by addition of the phytoestrogen with activation of ERs. Finally, AngII induced phosphorylation of heat shock factor-1 (HSF1) and decreased sirtuin-1 (SIRT1). In addition, AngII also caused an increase in distribution of IGF-2R molecules on cell membrane. In contrast, TSN reduced HSF1 phosphorylation and cell surface IGF-2R while elevating SIRT1 via ERs. TSN was capable of attenuating AngII-induced IGF-2R pathway and hypertrophy through ERs in H9c2 cardiomyoblast cells.

E2/ER ß Enhances Calcineurin Protein Degradation and PI3K/Akt/MDM2 Signal Transduction to Inhibit ISO-Induced Myocardial Cell Apoptosis.

Secretion of multifunctional estrogen and its receptor has been widely considered as the reason for markedly higher frequency of heart disease in men than in women. 17ß-Estradiol (E2), for instance, has been reported to prevent development of cardiac apoptosis via activation of estrogen receptors (ERs). In addition, protein phosphatase such as protein phosphatase 1 (PP1) and calcineurin (PP2B) are also involved in cardiac hypertrophy and cell apoptosis signaling. However, the mechanism by which E2/ERß suppresses apoptosis is not fully understood, and the role of protein phosphatase in E2/ERß action also needs further investigation. In this study, we observed that E2/ERß inhibited isoproterenol (ISO)-induced myocardial cell apoptosis, cytochrome c release and downstream apoptotic markers. Moreover, we found that E2/ERß blocks ISO-induced apoptosis in H9c2 cells through the enhancement of calcineurin protein degradation through PI3K/Akt/MDM2 signaling pathway. Our results suggest that supplementation with estrogen and/or overexpression of estrogen receptor ß gene may prove to be effective means to treat stress-induced myocardial damage.

Treatment with 17ß-Estradiol Reduced Body Weight and the Risk of Cardiovascular Disease in a High-Fat Diet-Induced Animal Model of Obesity.

Estrogen receptor α (ERα) and estrogen receptor ß (ERß) play important roles in cardiovascular disease (CVD) prevention. Recently, these estrogen receptors were reconsidered as an important treatment target of obesity leading to CVD. In this study, 17ß-estradiol (17ß-E) replacement therapy applied to high-fat diet-induced obese C57B male mice and ovariectomized (OVX) rats were evaluated, and the protective effects against high-fat diet-induced obesity were assessed in C57B mouse hearts. The results showed that 17ß-E treatment activated both ERα and ERß, and ERß levels increased in a dose-dependent manner in high-fat diet C57B mouse cardiomyocytes following 17ß-E treatment. Notably, an almost 16% reduction in body weight was observed in the 17ß-E-treated (12 µg/kg/day for 60 days) high-fat diet-induced obese C57B male mice. These results suggested that 17ß-E supplements may reduce CVD risk due to obesity.

Multi-Strain Probiotics Inhibit Cardiac Myopathies and Autophagy to Prevent Heart Injury in High-Fat Diet-Fed Rats.

High-fat diets induce obesity, leading to cardiomyocyte fibrosis and autophagy imbalance. In addition, no previous studies have indicated that probiotics have potential health effects associated with cardiac fibrosis and autophagy in obese rats. This study investigates the effects of probiotics on high-fat (HF) diet-induced obesity and cardiac fibrosis and autophagy in rat hearts. Eight-week-old male Wistar rats were separated randomly into five equally sized experimental groups: Normal diet (control) and high-fat (HF) diet groups and groups fed a high-fat diet supplemented with low (HL), medium (HM) or high (HH) doses of multi-strain probiotic powders. These experiments were designed for an 8-week trial period. The myocardial architecture of the left ventricle was evaluated using Masson's trichrome staining and immunohistochemistry staining. Key probiotics-related pathway molecules were analyzed using western blotting. Abnormal myocardial architecture and enlarged interstitial spaces were observed in HF hearts. These interstitial spaces were significantly decreased in groups provided with multi-strain probiotics compared with HF hearts. Western blot analysis demonstrated that key components of the TGF/MMP2/MMP9 fibrosis pathways and ERK5/uPA/ANP cardiac hypertrophy pathways were significantly suppressed in probiotic groups compared to the HF group. Autophagy balance is very important in cardiomyocytes. In this study, we observed that the beclin-1/LC3B/Atg7 autophagy pathway in HF was increased after probiotic supplementation was significantly decreased. Together, these results suggest that oral administration of probiotics may attenuate cardiomyocyte fibrosis and cardiac hypertrophy and the autophagy-signaling pathway in obese rats.

Secondhand Smoke Exposure Enhances Cardiac Fibrosis Effects on the Aging Rat Hearts.

BACKGROUND: Examining aging rats exposed to secondhand smoke (SHS) engenders changes in left ventricular remodeling due to age- or disease-dependent alterations. METHODS: Rats were placed in whole-body exposure chambers and exposed to 10 cigarettes. Filtered air was introduced into the chamber at a low rate. Rats were exposed to SHS for 30 min, twice a day, 5 days per week for 1 month. After 4 weeks SHS exposure, rats were sacrificed for morphological study with trichome staining and left ventricular remodeling related protein analysis using western blot. RESULTS: Characteristic fibrotic morphology in the left ventricle increased significantly with aging and exposure to SHS. Exposure to SHS elevated TGFß1/p-Smad2/3/CTGF and MMP2/MMP9 protein expression levels (p < 0.05). No significant differences in FGF-2 and UPA protein expression were noted as a result of SHS exposure. However, TIMP-1, TIMP-2, TIMP-3 and TIMP-4 protein expression were suppressed by SHS exposure. We also observed increased TGFß1/p-Smad2/3/CTGF (p < 0.01), FGF-2/UPA (p < 0.05) and decreased TIMPs protein expression levels. Corresponding MMP2 and MMP9 upregulation occurred with aging and exposure to SHS. TGFß1/p-Smad2/3/CTGF and FGF-2/UPA protein expression from SHS exposure were higher than that from aging. In contrast, MMP2 and MMP9 were increased in aging rats compared with SHS exposed rats (p < 0.05); however, TIMP-1 (p < 0.01), TIMP-2 (p < 0.01) and TIMP-3 (p < 0.05) were decreased. TIMP-4 protein expression levels were decreased compared with SHS exposed rats (p < 0.01). CONCLUSIONS: Aging and SHS exposure in rats will produce elevated fibrosis. Exposure to SHS will accelerate aging and left ventricular fibrosis.

ZAK induces cardiomyocyte hypertrophy and brain natriuretic peptide expression via p38/JNK signaling and GATA4/c-Jun transcriptional factor activation.

Cardiomyocyte hypertrophy is an adaptive response of heart to various stress conditions. During the period of stress accumulation, transition from physiological hypertrophy to pathological hypertrophy results in the promotion of heart failure. Our previous studies found that ZAK, a sterile alpha motif and leucine zipper containing kinase, was highly expressed in infarcted human hearts and demonstrated that overexpression of ZAK induced cardiac hypertrophy. This study evaluates, cellular events associated with the expression of two doxycycline (Dox) inducible Tet-on ZAK expression systems, a Tet-on ZAK WT (wild-type), and a Tet-on ZAK DN (mutant, Dominant-negative form) in H9c2 myoblast cells; Tet-on ZAK WT was found to increase cell size and hypertrophic marker BNP in a dose-dependent manner. To ascertain the mechanism of ZAK-mediated hypertrophy, expression analysis with various inhibitors of the related upstream and downstream proteins was performed. Tet-on ZAK WT expression triggered the p38 and JNK pathway and also activated the expression and nuclear translocation of p-GATA4 and p-c-Jun transcription factors, without the involvement of p-ERK or NFATc3. However, Tet-on ZAK DN showed no effect on the p38 and JNK signaling cascade. The results showed that the inhibitors of JNK1/2 and p38 significantly suppressed ZAK-induced BNP expression. The results show the role of ZAK and/or the ZAK downstream events such as JNK and p38 phosphorylation, c-Jun, and GATA-4 nuclear translocation in cardiac hypertrophy. ZAK and/or the ZAK downstream p38, and JNK pathway could therefore be potential targets to ameliorate cardiac hypertrophy symptoms in ZAK-overexpressed patients.

Cardio Protective Effects of Lumbrokinase and Dilong on Second-Hand Smoke-Induced Apoptotic Signaling in the Heart of a Rat Model.

Exposure to second-hand tobacco smoke (SHS) has been epidemiologically linked to heart disease among non-smokers. However, the molecular mechanism behind SHS-induced cardiac disease is not well known. This study found that SD rats exposed to cigarette smoke at a dose of 10 cigarettes for 30 min twice a day for 1 month had a reduced left ventricle-to-tibia length ratio (mg/mm), increased cardiomyocyte apoptosis by TUNEL assay and a wider interstitial space by H&E staining. However, lumbrokinase and dilong both reversed the effects of SHS. Western blotting demonstrated significantly increased expression of the pro-apoptotic protein caspase-3 in the hearts of the rats exposed to SHS. Elevated protein expression levels of Fas, FADD and the apoptotic initiator activated caspase-8, a molecule in the death-receptor-dependent pathway, coupled with increased t-Bid and apoptotic initiator activated caspase-9 were found. Molecules in the mitochondria-dependent pathway, which disrupts mitochondrial membrane potential, were also found in rats exposed to SHS. These factors indicate myocardial apoptosis. However, treatment with lumbrokinase and dilong inhibited SHS-induced apoptosis. Regarding regulation of the survival pathway, we found in western blot analysis that cardiac protein expression of pAkt, Bcl2, and Bcl-xL was significantly down-regulated in rats exposed to SHS. These effects were reversed with lumbrokinase and dilong treatment. The effects of SHS on cardiomyocytes were also found to be mediated by the Fas death receptor-dependent apoptotic pathway, an unbalanced mitochondria membrane potential and decreased survival signaling. However, treatment with both lumbrokinase and dilong inhibited the effects of SHS. Our data suggest that lumbrokinase and dilong may prevent heart disease in SHS-exposed non-smokers.

Nerve Regeneration Potential of Protocatechuic Acid in RSC96 Schwann Cells by Induction of Cellular Proliferation and Migration through IGF-IR-PI3K-Akt Signaling.

Peripheral nerve injuries, caused by accidental trauma, acute compression or surgery, often result in temporary or life-long neuronal dysfunctions and inflict great economic or social burdens on the patients. Nerve cell proliferation is an essential process to restore injured nerves of adults. Schwann cells play a crucial role in endogenous repair of peripheral nerves due to their ability to proliferate, migrate and provide trophic support to axons via expression of various neurotrophic factors, such as the nerve growth factor (NGF), especially after nerve injury. Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid, isolated from the kernels of Alpinia oxyphylla Miq (AOF), a traditional Chinese herbal medicine the fruits of which are widely used as a tonic, aphrodisiac, anti-salivation and anti-diarrheatic. This study investigated the molecular mechanisms by which PCA induces Schwann cell proliferation by activating IGF-IR-PI3K-Akt pathway. Treatment with PCA induces phosphorylation of the insulin-like growth factor-I (IGF-I)-mediated phosphatidylinositol 3 kinase/serine - threonine kinase (PI3K/Akt) pathway, and activates expression of cell nuclear antigen (PCNA) in a dose-dependent manner. Cell cycle analysis after 18 h of treatment showed that proliferation of the RSC96 cells was enhanced by PCA treatment. The PCA induced proliferation was accompanied by modulation in the expressions of cell cycle proteins cyclin D1, cyclin E and cyclin A. Knockdown of PI3K using small interfering RNA (siRNA) and inhibition of IGF-IR receptor resulted in the reduction in cell survival proteins. The results collectively showed that PCA treatment promoted cell proliferation and cell survival via IGF-I signaling.

Cell Cycle Regulation in the Estrogen Receptor Beta (ESR2)-Overexpressing Hep3B Hepatocellular Carcinoma Cell Line.

Epidemiological studies and experimental data have shown that the incidences of hepatocellular carcinoma in men are more frequent than in women. Evidence suggests that imbalance of hormones, including estrogen, androgen, prolactin, and growth hormone, modifies liver tumorigenesis. In this present study, we investigated how estrogen and estrogen receptor 2 (ESR2), regulates the cell cycle mechanism in Hep3B hepatocellular carcinoma cell line. Our results showed that ESR2 overexpression in the presence of 10⁻8 M 17-ß-estradiol downregulated c-myc and cyclin D1 expression and simultaneously upregulated p27 expression. However, flow cytometry and MTT assays showed only minor G1 phase arrest without affecting cell viability. Taken together, these observations indicate that ESR2 is required to lower tumorigenesis in males by altering cell cycle proteins in a ligand-dependent manner.

Gelsolin (GSN) induces cardiomyocyte hypertrophy and BNP expression via p38 signaling and GATA-4 transcriptional factor activation.

Cardiomyocyte hypertrophy is an adaptive response of the heart to various types of stress. During the period of stress accumulation, the transition from physiological hypertrophy to pathological hypertrophy results in the promotion of heart failure. Gelsolin (GSN) is a member of the actin-binding proteins, which regulate dynamic actin filament organization by severing and capping. Moreover, GSN also regulates cell morphology, differentiation, movement, and apoptosis. In this study, we used H9c2 and H9c2-GSN stable clones in an attempt to understand the mechanisms of GSN overexpression in cardiomyocytes. These data showed that the overexpression of GSN in H9c2-induced cardiac hypertrophy and increased the pathological hypertrophy markers atrial natriuretic peptide brain natriuretic peptide. Furthermore, we found that E-cadherin expression decreased with the overexpression of GSN in H9c2, but ß-catenin expression increased. These data presume that the cytoskeleton is loose. Further, previous studies show that the mitogen-activated protein kinase pathway can induce cardiac hypertrophy. Our data showed that p-p38 expression increased with the overexpression of GSN in H9c2, and the transcription factor p-GATA4 expression also increased, suggesting that the overexpression of GSN in H9c2-induced cardiac hypertrophy seemed to be regulated by the p38/GATA4 pathway. Moreover, we used both the p38 inhibitor (SB203580) and GSN siRNA to confirm our conjecture. We found that both of these factors significantly suppressed gelsolin-induced cardiac hypertrophy through p38/GATA4 signaling pathway. Therefore, we predict that the gene silencing of GSN and/or the downstream blocking of GSN along the p38 pathway could be applied to ameliorate pathological cardiac hypertrophy in the future.

Effects of garlic oil on interleukin-6 mediated cardiac hypertrophy in hypercholesterol-fed hamsters.

Hypercholesterol diets are the major causes of cardiac hypertrophy and various cardiac disorders. The purpose of this study is to evaluate the effects of garlic oil on cardiac hypertrophy induced by hypercholesterol diets. Golden Syrian hamsters were fed with 2% cholesterol or 2% cholesterol plus 1% garlic oil for 2 months. Heart architecture changes were measured by hematoxylin-eosin staining and the molecular mechanism was determined by western blotting. Garlic oil reduced whole-heart weight to bone weight ratio, and left ventricle weight to bone weight ratio in the cholesterol-fed group. Moreover, the garlic oil group showed significantly reduced interleukin-6, phosphorylated (p)-extracellular signal-regulated kinase-5, p-mitogen-activated protein kinase-5, calcineurin, nuclear transcription factor of nuclear factor of activated T-cells-3 and p-GATA binding protein 4 when compared with the cholesterol group. However, no changes were observed in gp-130, signal transducer and activator of transcription-3, p-P38 and p-Jun N-terminal kinases protein levels in all groups. The results show that garlic oil may be useful in the treatment of hypertrophy-associated cardiovascular diseases.

SHSST cyclodextrin complex prevents the fibrosis effect on CCl4-induced cirrhotic cardiomyopathy in rats through TGF-ß pathway inhibition effects.

Patients with liver cirrhosis also have subtle cardiac structure or function abnormalities. This cardiac dysfunction commonly occurs in 56% of waiting orthotopic liver transplantation (OLT) patients and is defined as cirrhotic cardiomyopathy (CCM). Up to now, there is no standard treatment because CCM does not have a solidly established diagnosis and is based on high clinical suspicion. The liver function of CCM is particularly limited, making patients vulnerable to more drug treatments. Here, we use silymarin (100 mg/kg/day), baicalein (30 mg/kg/day), San Huang Shel Shin Tang (SHSST, 30 mg/kg/day) and ß-cyclodextrin modified SHSST (SHSSTc, 30 and 300 mg/kg/day) treatments for a CCl4-induced CCM rat model. The results show that silymarin, baicalein and SHSST treatments can only slightly reduce the collagen accumulation in CCM rat hearts. However, SHSSTc treatment protects the heart in CCM and significantly inhibits collagen acumination and the fibrosis regulating transforming growth factor-ß (TGF-ß) pathway expression. SHSSTc treatments further reduced the heart weight and the ratio between left ventricular weight (LVW) and tibia length (TL). This experimental data show that water solubility improved ß-cyclodextrin modified Chinese herbal medicine formula (SHSSTc) can provide an excellent heart protection effect through TGF-ß pathway inhibition.

Suppression of plasminogen activators and the MMP-2/-9 pathway by a Zanthoxylum avicennae extract to inhibit the HA22T human hepatocellular carcinoma cell migration and invasion effects in vitro and in vivo via phosphatase 2A activation.

This study shows that the ECM degradation-associated pathway, including uPA and tPA and the downstream MMP-2/-9 protein, was significantly suppressed in HA22T cells treated with a Zanthoxylum avicennae extract (YBBE). The endogenous inhibitors, including TIMP-1/-2 and PAI-1, were enhanced in HA22T cells by the YBBE treatment. The expression of MMP-2/-9 and TIMP-1/-2 was respectively assessed by using RT-PCR and a zymography assay. The mRNA levels and enzymatic activity of MMP-2/-9 were down-regulated by the YBBE treatment in a dose-dependent manner, while the TIMP-1/-2 levels were conversely markedly increased. The PP2A siRNA or PP2A inhibitor totally reversed the YBBE effects, confirming the essential role of PP2A in YBBE inhibiting the HA22T cell migration and invasion effects. Xenografted animal experiments on nude mice demonstrated similiar results to the in vitro system. Both the in vitro and in vivo models clearly demonstrate that YBBE inhibited the highly metastatic HA22T liver cancer cell migration and invasion effects through PP2A activation.

Effect of Vasicinone against Paraquat-Induced MAPK/p53-Mediated Apoptosis via the IGF-1R/PI3K/AKT Pathway in a Parkinson's Disease-Associated SH-SY5Y Cell Model.

Vasicinone is a quinazoline alkaloid isolated from the Adhatoda vasica plant. In this study, we explored the neuroprotective effect and underlying molecular mechanism of vasicinone against paraquat-induced cellular apoptosis in SH-SY5Y cells. Vasicinone reduced the paraquat-induced loss of cell viability, rescued terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL)-positive apoptotic nuclei, and suppressed generation of reactive oxygen species (ROS) in a dose-dependent manner. Western blotting analysis revealed that vasicinone increased the phosphorylation of IGF1R/PI3K/AKT cell survival signaling molecules and downregulated the paraquat-induced, mitogen-activated protein kinase (MAPK)/c-Jun N-terminal kinase (JNK)-mediated apoptotic pathways compared to that observed in cells not treated with vasicinone. This protection depended critically on the activation of IGF1R, and the silencing of IGF1R by siRNA completely abrogated the protective effect of vasicinone in SH-SY5Y cells. Our findings indicated that vasicinone is a potential candidate for the treatment of Parkinson's disease and possibly other oxidative stress-related neurodegenerative disorders.

Potential phytoestrogen alternatives exert cardio-protective mechanisms via estrogen receptors.

The 17 beta-estradiol (E2) is a sex hormone that is most abundant and most active estrogen in premenopausal women. The importance of E2 in providing cardioprotection and reducing the occurrence of heart disease in women of reproductive age has been well recognized. There are three subtype of estrogen receptors (ERs), including ERα, ERß and GPR30 have been identified and accumulating evidence reveal their roles on E2-mediated genomic and nongenomic pathway in cardiomyocytes against various cardiac insults. In this review, we focus on the estrogen and ERs mediated signaling pathways in cardiomyocytes that determines cardio-protection against various stresses and further discuss the clinical implication of ERs and phytoestrogens. Further we provide some insights on phytoeostrogens which may play as alternatives in estrogen replacement therapies.

Hypoxia Augments Increased HIF-1α and Reduced Survival Protein p-Akt in Gelsolin (GSN)-Dependent Cardiomyoblast Cell Apoptosis.

Cytoskeleton filaments play an important role in cellular functions such as maintaining cell shape, cell motility, intracellular transport, and cell division. Actin-binding proteins (ABPs) have numerous functions including regulation of actin filament nucleation, elongation, severing, capping, cross linking, and actin monomer sequestration. Gelsolin (GSN) is one of the actin-binding proteins. Gelsolin (GSN) is one of the actin-binding proteins that regulate cell morphology, differentiation, movement, and apoptosis. GSN also regulates cell morphology, differentiation, movement, and apoptosis. In this study, we have used H9c2 cardiomyoblast cell and H9c2-GSN stable clones to understand the roles and mechanisms of GSN overexpression in hypoxia-induced cardiomyoblast cell death. The data show that hypoxia or GSN overexpression induces HIF-1α expression and reduces the expression of survival markers p-Akt and Bcl-2 in H9c2 cardiomyoblast cells. Under hypoxic conditions, GSN overexpression further reduces p-Akt expression and elevates total as well as cleaved GSN levels and HIF-1α levels. In addition, GSN overexpression enhances apoptosis in cardiomyoblasts under hypoxia. Hypoxic challenge further induced activated caspase-3 and cell death that was attenuated after GSN knock down, which implies that GSN is a critical therapeutic target against hypoxia-induced cardiomyoblast cell death.

Tanshinone IIA Prevents Leu27IGF-II-Induced Cardiomyocyte Hypertrophy Mediated by Estrogen Receptor and Subsequent Akt Activation.

IGF-IIR plays important roles as a key regulator in myocardial pathological hypertrophy and apoptosis, which subsequently lead to heart failure. Salvia miltiorrhiza Bunge (Danshen) is a traditional Chinese medicinal herb used to treat cardiovascular diseases. Tanshinone IIA is an active compound in Danshen and is structurally similar to 17[Formula: see text]-estradiol (E[Formula: see text]. However, whether tanshinone IIA improves cardiomyocyte survival in pathological hypertrophy through estrogen receptor (ER) regulation remains unclear. This study investigates the role of ER signaling in mediating the protective effects of tanshinone IIA on IGF-IIR-induced myocardial hypertrophy. Leu27IGF-II (IGF-II analog) was shown in this study to specifically activate IGF-IIR expression and ICI 182,780 (ICI), an ER antagonist used to investigate tanshinone IIA estrogenic activity. We demonstrated that tanshinone IIA significantly enhanced Akt phosphorylation through ER activation to inhibit Leu27IGF-II-induced calcineurin expression and subsequent NFATc3 nuclear translocation to suppress myocardial hypertrophy. Tanshinone IIA reduced the cell size and suppressed ANP and BNP, inhibiting antihypertrophic effects induced by Leu27IGF-II. The cardioprotective properties of tanshinone IIA that inhibit Leu27IGF-II-induced cell hypertrophy and promote cell survival were reversed by ICI. Furthermore, ICI significantly reduced phospho-Akt, Ly294002 (PI3K inhibitor), and PI3K siRNA significantly reduced the tanshinone IIA-induced protective effect. The above results suggest that tanshinone IIA inhibited cardiomyocyte hypertrophy, which was mediated through ER, by activating the PI3K/Akt pathway and inhibiting Leu27IGF-II-induced calcineurin and NFATC3. Tanshinone IIA exerted strong estrogenic activity and therefore represented a novel selective ER modulator that inhibits IGF-IIR signaling to block cardiac hypertrophy.

Exercise training enhanced SIRT1 longevity signaling replaces the IGF1 survival pathway to attenuate aging-induced rat heart apoptosis.

Cardiovascular disease is the second leading cause of death (9.1 %) in Taiwan. Heart function deteriorates with age at a rate of 1 % per year. As society ages, we must study the serious problem of cardiovascular disease. SIRT1 regulates important cellular processes, including anti-apoptosis, neuronal protection, cellular senescence, aging, and longevity. In our previous studies, rats with obesity, high blood pressure, and diabetes exhibiting slowed myocardial performance and induced cell apoptosis were reversed via sports training through IGF1 survival signaling compensation. This study designed a set of experiments with rats, in aging and exercise groups, to identify changes in myocardial cell signaling transduction pathways. Three groups of three different aged rats, 3, 12, and 18 months old, were randomly divided into aging groups (C3, A12, and A18) and exercise groups (E3, AE12, and AE18). The exercise training consisted of swimming five times a week with gradual increases from the first week from 20 to 60 min for 12 weeks. After the sports training process was completed, tissue sections were taken to observe cell organization (hematoxylin and eosin (H&E) stain) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays) and to observe any changes in the myocardial tissues and proteins (Western blotting). The experimental results show that cardiomyocyte apoptotic pathway protein expression increased with age in the aging groups (C3, A12, and A18), with improvement in the exercise group (E3, AE12, and AE18). However, the expression of the pro-survival p-Akt protein decreased significantly with age and reduced performance. The IGF1R/PI3K/Akt survival pathway in the heart of young rats can indeed be increased through exercise training. As rats age, this pathway loses its original function, even with increasing upstream IGF1. However, levels of SIRT1 and its downstream target PGC-1α were found to increase with age and compensatory performance. Moreover, exercise training enhanced the SIRT longevity pathway compensation instead of IGF1 survival signaling to improve cardiomyocyte survival.